ds-site/Classes/UserFunction/CodeHighlighting.php

<?php

declare(strict_types=1);

/*
 * Copyright (C) 2019 Daniel Siepmann <coding@daniel-siepmann.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

namespace DanielSiepmann\DsSite\UserFunction;

use Highlight\Highlighter;
use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;

/**
 * Highlights the current value via library.
 * Returns HTML Markup with css classes for proper highlighting.
 */
class CodeHighlighting
{
    /**
     * @var ContentObjectRenderer
     */
    public $cObj;

    public function preTag(string $content, array $config): string
    {
        $highlighter = new Highlighter();
        $highlighter->setClassPrefix('');
        $code = $this->cObj->data[$this->cObj->currentValKey];
        $code = htmlspecialchars_decode(trim($code));

        try {
            // Highlight some code.
            $highlighted = $highlighter->highlightAuto($code);
            $content = '<pre><code>' . $highlighted->value . '</code></pre>';
        } catch (\DomainException $e) {
            $content = '<pre><code>' . $code . '</code></pre>';
        }

        return $content;
    }
}